Conventionally, as a contact switching device, as described in Japanese Patent Application Laid-Open No. 2005-203306, there has been a DC relay including contact pairs each having contacts performing interlockingly switching, a contact containing case that contains the contact pairs, and a drive portion to drive switching of at least one of the contacts, wherein the drive portion and the contact containing case are fixed by screwing in a switching direction of the contacts.
In the foregoing DC relay, as shown in FIG. 1, first, second movable members 41, 42 move vertically, by which first, second movable contacts 31, 32 contact and depart from first, second fixed contacts 21, 22, and third, fourth movable contacts 33, 34 contact and depart from third, fourth fixed contacts 33, 34.